High molecular weight fatty piperazine amphoteric surfactants



United States Patent 3,385,858 HIGH MOLECULAR WEIGHT FATTY PIPERAZINE AMPHOTERKC SURFACTANTS Jacob Katz, Providence, RI. (1224 Mention Road, Ashton, RI. 02904) No Drawing. lFiled Oct. 24, 1965, Ser. No. 504,996 Claims. (Cl. 260-268) ABSTRACT OF THE DISCLOSURE The present disclosure describes piperazine amphoteric surfactants made by combining N aminoethyl piperazine, N hydroethyl piperazine, N aminopropyl piperazine, N hydroxypropyl piperazine and N,N' aminoethyl piperazine with a high molecular weight fatty acid, such as oleic acid, tall oil fatty acid, cocoanut fatty acid, or sebacic acid, followed by reaction with acrylonitrile or methlacrylate. Then the resultant compound is saponified.

RCOOH HzNCHzCHaN RC 0 OH HOCHzCHzN The final product may be used in shampoos, in soaps, for textile scouring, and for other uses.

The present application relates to novel surfactants, and it particularly relates to a high molecular weight fatty heterocyclie surfactant having high effectiveness in a wide variety of acidities and alkalinities.

It is among the objects of the present invention to provide a highly effective detergent which will maintain a high fine bubble foam over long periods of time in textile processing, without deterioration or loss of effective foam properties and without decreasing the volume of the foam regardless of the change in pH, whether it become strongly acid or become strongly alkaline, regardless of the salts that may be present or the pH of the bath in which the foam is being produced, and which will have unusually high corrosive inhibiting properties and which may be widely utilized in metal processing such as electroplating, radiator liquids, and coolants for metal working processes.

The preferred oil and water soluble surface active compounds have the following general formula:

where R represents a hydrocarbon or alkyl group containing from 7 to 21 carbon atoms, and where H may be replaced by R, and where R R R are short chain hydrocarbon or alkyl groups containing l to 6 carbon atoms, and where X represents either oxygen or nitrogen taking the form of an ether or secondary or tertiary amine linkages.

The alkali metal salts of these fatty complexes are water soluble and are versatile adjuncts in such diverse fields as cosmetic and shampoo preparations, industrial and household cleaners, deter-gent and scouring agents for processing textiles, emulsifiers and corrosion inhibitors.

These compounds are anionic in basic solution and cationic in acid solution; and in the range of pH 5.0 to 9.0, they exhibit both cationic and anionic properties, being truly amphoteric.

As fatty heterocyclic nitrogen carboxylic acids, they are RiCON ice soluble in polar and non-polar solvents, and may be neutralized with amines to form oil soluble salts. Both the carboxylic acids and their amine salts are excellent film forming compounds, exhibiting outstanding corrosion inhibiting properties.

They are effective as petroleum additives, detergents, asphalt wetting and anti-stripping agents and biocidal agents.

To give the chemical equations which are involved in making the above compounds, coconut fatty acid, oleic fatty acid, tall oil fatty acid, stearic acid or sebacic acid are combined starting at 300 F. and increasing up to 450 F. with an aliphatic long chain piperazine desirably having at least one terminal primary amino group or a short chain hydroxyalkyl group.

The polyamiue is desirably aminoethyl piperazine or hydroxye-thyl piperazine which reacts as set forth in the following equations:

CHzCH:

NH RCONH CHsCHzN CHzCHz OHQCHE NCHzCHsOH CHzCH:

In the Equations I and II, R is a fatty group having 8 to 22 carbon atoms and the reaction is desirably carried out starting at about 250 to 350 F. under a low vacuum for one to three hours followed by continuing a reaction at about 300 to 450 F. for four to eight hours at a higher vacuum.

Then to one mol of these heterocyclic compounds is added in dropwise fashion one moi of an acrylic compound, such as acrylonitrile or methyl acrylate at a temperature of to F.

The acrylic compounds should desirably have one unsaturated double bond in the aliphatic chain and contain from one to four carbon atoms, and they have terminal CN or COOH groups.

They also may have methyl, ethyl or propyl groups either as terminal groups or as side chains.

Desirably, a three-neck flask is utilized with a condenser connected to one neck, an agitator connected through the other neck and a funnel and thermometer is connected in the third neck.

The acrylic compound is dropped for about one hour, followed by heating for about one and one-half to three hours at to 230 F. with the final processing and elevated temperature treatment taking place at 15 to 18 inches vacuum.

After this combination, with the acrylic compounds, has been completed, the reaction product is treated with equimolar proportions of caustic soda in 25% concentration and at a temperature of about 200 F. for about one and one-half to three hours.

In these compounds, the R group is desirably derived from oleic acid, tall oil fatty acid or coconut fatty acid and less desirably from sebacic acid.

They are surprisingly effective as detergents, emulsifiers and corrosion inhibitors in very small concentrations. They may be used in shampoos, in soaps, emulsion polymerization, as oven cleaners, as industrial cleaners, in electroplating, in cosmetics, for textile scouring, dyeing and lubrication, in sanitizers, in paints, and in leather treating.

The piperazine derivatives are synthesized by the reaction of fatty esters, acids or acid chlorides with substituted piperazine compounds as N-aminoethyl piperazine, N-

3 hydroxyethyl piperazine, N-aminopropyl piperazine, N- hydroxypropyl piperazine and N,N-aminoethyl piperazine.

EXAMPLE I Into a three-neck two liter flask was charged one mol of lauric acid and one mol of aminoethyl piperazine.

The contents was heated to 150l70 C. until 1 mol (18 milliliters) of water was recovered in the moisture trap. The dodecyl amidoethyl piperazine was cooled to 60 C. and one mol of methyl aerylate or acrylonitrile was slowly added through a dropping funnel over a period of one hour.

The temperature was gradually raised to 100 C. and held for two hours at which time the addition reaction was completed. The one mol of sodium hydroxide dissolved in 200 milliliters of water was added to the flask and the mixture heated with stirring at 90-100 C. until the nitrile group was completely saponified at which time the flask was purged with nitrogen to remove all traces of ammonia and the product was then diluted to 50% active matter with hot water.

The aqueous solution of the dodecyl amidoethyl piperazine sodium propionate was a yellow-brown viscous solution. Dilute solutions showed good stability to acids and alkalies, high foaming characteristics, excellent detergency and surfactant properties.

EXAMPLE II One mol of methyl stearate and one mol of hydroxyethyl piperazine was charged into a three-neck two-liter flask equipped with a thermometer, agitator and receiving trap.

The mixture was heated to 175 C. and held at this temperature until one mol of methyl alcohol was recovered in the receiver.

The flask was then cooled to 60 C. and five grams of a solution of sodium methylate in methyl alcohol was added as catalyst followed by one mol of methylacrylate over a period of one hour.

The temperature was then raised to 75 C. and held at this temperature until test samples showed complete reaction between the hydroxy group and the methyl acrylate to form the ethoxy methyl propionate.

The sodium salt was formed by the saponification of the methyl ester with 20% caustic soda (200 grams) at 100 C. The resulting compound is a white paste, soluble in water and stable to acids and alkalies.

It showed good scouring and foaming properties on all types of fabrics and left the fabrics with a nice soft hand (finish). It showed good emulsifying properties and made stable mineral oil emulsions of the O/W type.

The methyl acrylate adducts of these long chain heterocyclic nitrogen compounds are oil soluble surfactants. They are dispersible in water, lowering the surface tension of water to dynes/centimeter at 0.1 concentration.

The compounds are completely soluble in alcohols, ketones, ethers, and aromatic and aliphatic hydrocarbons. They act as good corrosion inhibitors, filming compounds, dewatering agents and show selective fungicidal and biocidal activity, either by themselves or in the form of the acetate of hydrochloride salt.

The water soluble alkali propionates of these long chain heterocyclic nitrogen compounds have been found to be detergents in the wet processing of textiles and leather, excellent wetting and emulsifying agents, dyeing assistants and finishing compounds.

As petroleum additives, they serve as corrosion inhibitors for aqueous salt and acid solutions, filming compounds on metals, dewatering agents, in the mining industry as flotation agents, frothing compounds and selective mineral wetting agents.

In the pharmaceutical industry, these compounds offer combined detergeney with germicidal properties.

The alkanoic acids of these long chain heterocyclic nitrogen compounds combine with amines to form both oil and water soluble emulsifiers with corrosion inhibiting properties.

EXAMPLE III where S or T include a fatty acid amide group having 8 to 22 carbon atoms and the other S or T group contains an alkyl chain with or without intermediate ether or amino linkages containing a terminal carboxylate groupmg.

EXAMPLE IV CII -CII;

HOC lIiN NH methyl stenrute CH CH CIIy-CII; O HOCZH-lN N C C17H CH -C 2 GH -CH O CHBO OCCI'IZCHQOCHZOHQN N( i 01111 CHz-C 2 The terminal CH group may be replaced by alkali metal.

In the process of producing the above identified surfactants, the following are the important steps:

(a) Slow addition of the acryiate,

(b) The use of methyl acrylate,

(c) The temperature range from 140 to 212 F. or

C. to C.,

(d) The finishing operation at higher temperature,

(e) The stripping of any excess,

(f) The production of 98% yield.

This procedure and the resultant compounds are not shown in Mannheimer Patent No. 2,528,379, who produces a dicarboxylic compound of quite different properties. The dicarb-oxylic acid is quite different in this respect from the monocarboxylic compound. Moreover, Mannheimer does not obtain biocidal properties since he must mix with quaternary ammonium compounds.

Furthermore, Mannheimer has to use chloracetic or sodium chloracetate which will form a betaine or a quaternary compound in which the l-nitrogen of the ring must be quaternized by the chloroacetate as follows:

Therefore, Mannheimer has neither the product, nor the process of applicant.

Rehberg, Patent No. 2,504,151, describes reacting methyl acrylate with furfuryl alcohol with 30% yield after 24 hours Example 23). The temperature is below 35 C. It will be noted that the acrylate is added to the alcohol in the presence of sodium.

Where in Example 1, a 60% yield is obtained it is necessary to use a molar ratio of 2 to 8 at a temperature below 40 C. and here again sodium must be used and the butanol is added.

De Groote, Patent No. 2,468,180, relates to a process for breaking or resolving petroleum emulsions using cationic glyoxalidines (imidazolines). It discloses the use of di-quaternary ammonium derivatives of fatty imidazolines for use as emulsion breakers. It is no way pertains to water soluble amphoteric surfactants based on amino carboxylic acids.

Stromberg, Patent No. 2,987,515, relates to diurethanes of imidazolines as corrosion inhibitors. These compounds may have poor or fair corrosion inhibiting properties quite diflerent from the applicants. The applicant has quite different alkyl heterocyclic propionitriles and propionate esters which are excellent oil soluble corrosion inhibitors. For example, applicants compounds which are water soluble have the unexpected property of corrosion inhibition in aqueous solution. Steel wool pads, which normally rust and disintegrate in 24 hours when immersed in tap water, remain clean and in perfect condition when the tap water has 1% to 5% of the applicants products.

EXAMPLE V l-laurylamidoethyl, 4-sodium carboxyethyl piperazine is prepared using methyl acrylate.

One mole of methyl laurate and one mole aminoethyl piperazine were added to a three neck flask equipped with a stirrer, Stark-Dean trap, condenser and thermometer. The reaction is carried out at ISO-215 C. resulting in a yield of 98% l-laurylamidoethyl piperazine (HCl number 205 The product was cooled to just above its melting point (65 C.) and one mole of methyl acrylate was added slowly at this temperature. After the addition of the methyl acrylate the temperature was raised to 90 C. and the reaction mass stirred for an additional three hours.

At the end of this time, the tertiary amine content by the phenyl isocyanate method was 95% of theoretical.

The l-laurylamidoethyl methylcarboxyethyl piperazine was saponified with one mole of caustic soda dissolved in one liter of water.

The resulting product was a soft white water soluble paste. It is amphoteric in nature being soluble in both acidic and basic solutions and does not precipitate in the presence of calcium or magnesium ions. The product is an excellent scouring agent for cotton, rayon, wool and synthetic fibers.

EXAMPLE VI l-laurylamido, 4-sodium carboxyethoxyethyl piperazine was synthesizised by reacting one mole of hydroxyethyl piperazine with one mole of methyl laurate to form the l-laurylamido, 4-hydroxyethyl piperazine (93% yield), to which was added one mole of methyl acrylate as described in the previous example.

This product was then saponified with aqueous caustic soda to form a paste containing 33% active matter which had excellent detergent and wetting properties in both basic and acidic scouring baths.

Having now particularly described and ascertained the nature of the invention, and in what manner the same is to be performed, what is claimed is:

1. As a compound, l-(dodecyl-amidoethyl)-4-carbomethoxyethyl-piperazine.

2. A piperazine having the following structural formula:

CHz-CHz N-CzH4-O-CzHCOOR1 CHFCH:

where R is a long chain alkyl group having from 8 to 22 carbon atoms and R is selected from the group consisting of hydrogen and an alkali metal.

3. A piperazine having the following structural formula:

hydrogen and an alkali metal.

4. As a compound,

CHz-Cl-h NCH2CH2COONa CHz-CH:

C lzHzaC O N CzH-rN 5. As a compound,

CH2CH2 O N-iiCnHas CHQO O C CHzCHgO CHzCH2N References Cited Hromatka et al.: Monatsh. Chem, vol. 93 (1962), pp. 128892.

HENRY R. J ILES, Primary Examiner. 

